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Wye-Delta part V

First off an apology to acjourneyman, I should learn to read a little closer. These are the original contactors according to the starter manufacturer Cutler-Hammer and the Trane starter ID #. That's why I plan on contacting them on Monday, hell I may call Trane also. The more the merrier. Guys, thanks alot for all your advice. It is truly appreciated-GEO

Wye-Delta Grand Finale'

As promised I got all my answers today. The contactor size has nothing to with amps or volts (go figure) NEMA sizing only has to do with motor horsepower. The motor I'm dealing with is 240 horsepower and that is border line between a size 5 and 6 contactor, not a size 4 as is in there now. That would explain all the extra burnt contacts sets I found laying on the work bench. I think they have been changing contacts every year since 1982. That year also played a key role to my fact finding. That's the year Trane change venders with their starters from G/E to Cutler-Hammer, now Eaton, Cutler-Hammer. Ironic part of it all is the customer won't want to spend the money to upgrade to the right size contactors. It is their chiller and I'm only the messenger. Again thanks to all.-GEO

As promised I got all my answers today. The contactor size has nothing to with amps or volts (go figure) NEMA sizing only has to do with motor horsepower. The motor I'm dealing with is 240 horsepower and that is border line between a size 5 and 6 contactor, not a size 4 as is in there now. That would explain all the extra burnt contacts sets I found laying on the work bench. I think they have been changing contacts every year since 1982. That year also played a key role to my fact finding. That's the year Trane change venders with their starters from G/E to Cutler-Hammer, now Eaton, Cutler-Hammer. Ironic part of it all is the customer won't want to spend the money to upgrade to the right size contactors. It is their chiller and I'm only the messenger. Again thanks to all.-GEO

1st of all, it is 57% on each leg V x A x 1.73. That's why it is called a reduced voltage start because you have the windings in series. You have to remember, "S" is already pulled in before amperage is applied. 1M is pulled in by the aux of "S" and you are tying together 1/2 of a winding in series so the contact is not seeing the full brunt of current. I have seen this on a R-113, Carrier 19C that took almost one minute to get to speed. Scared the hell out of me the first time I started it because I had only been exposed to 460 volt chillers.

Wye-Delta Epilog

Stickerhead; Thanks for the comeback, but I had already had gotten my answers from Tech. Services @ Eaton Cutler- Hammer who originally manufactured the starter for Trane (according to Trane guidelines). Even in a Y/D starter all current in, matches all the current out, as in locked rotor and ramp up. The problem was not one of lack of acceleration on start-up, but undersized contactors, as the motor was up to speed within 10 seconds-GEO I'm closed

so the problem was indeed undersized contactors from trane??
is there a service bulletin??????????

Originally Posted by ga1279

Stickerhead; Thanks for the comeback, but I had already had gotten my answers from Tech. Services @ Eaton Cutler- Hammer who originally manufactured the starter for Trane (according to Trane guidelines). Even in a Y/D starter all current in, matches all the current out, as in locked rotor and ramp up. The problem was not one of lack of acceleration on start-up, but undersized contactors, as the motor was up to speed within 10 seconds-GEO I'm closed

I WILL SELL WORK,GENERATE BUSINESS, GO GET NEW CUSTOMERS!
YOU SHUT THE HELL UP AND QUIT RUNNING YOUR MOUTH!

Stickerhead; Thanks for the comeback, but I had already had gotten my answers from Tech. Services @ Eaton Cutler- Hammer who originally manufactured the starter for Trane (according to Trane guidelines). Even in a Y/D starter all current in, matches all the current out, as in locked rotor and ramp up. The problem was not one of lack of acceleration on start-up, but undersized contactors, as the motor was up to speed within 10 seconds-GEO I'm closed

Wye-Delta (That's all Folks)

I have no idea, except to say that since the chiller[s] have been in service since Jan 1982 I would not waste my time trying for a service bulletin or compensation. The original building owners (when the chillers were installed) were actually lead to believe that changing contacts every year was part of the annual inspection. I also find it curious that it took 27 years to find the real problem. In that time the owners spent enough money to replace both starters completely. Oh well life goes on.-GEO.